An automotive vehicle powered fully or partially by an electric motor may be referred to as an electric vehicle (EV) or a plug-in electric vehicle with a gasoline engine (PHEV). As is well known in the art, such vehicles include a high-voltage (HV) battery or batteries for supplying power to the electric motors thereof.
Such electric vehicles typically provide for charging such HV batteries using a battery charger module mounted on-board the vehicle. The on-board battery charger module may be supplied with 85 to 265 volt alternating current (AC) power through a vehicle charge socket configured to interface with a charge coupler that is in communication with an electrical utility power grid. The on-board battery charger module is provided in communication with the vehicle HV batteries, and is configured to rectify electrical power from the utility AC power grid for storage by the vehicle HV batteries.
For the on-board battery charger module to perform its main function, AC electric power is required at the input to the module. Sensors are normally used to measure the voltage and current levels of the AC power supplied to the module. EV and PHEV on-board diagnostics may require that the battery charger module understand and/or verify if an AC voltage sensor associated with the battery charger module is functioning properly.
Electrical power from the AC power grid supply may be interrupted due to a variety of reasons. For example, the AC power supply may be interrupted as a result of instability in the electrical power grid, a fault associated with the charge coupler, a fault associated with the vehicle charge socket, a fault associated with vehicle wiring, or other reasons. These various reasons that may cause an interruption of AC power make it difficult to diagnose whether an AC voltage sensor in the on-board battery charger module is faulty, or whether something outside of the battery charger module is causing an interruption in the AC input voltage.
As a result, problems outside of the on-board battery charger module may cause diagnostics to incorrectly determine that an AC voltage sensor is faulty. Moreover, if such a sensor fails, the on-board battery charger module will not be able to determine if the AC electrical power supply is present and/or stable.
The typical solution to such problems would be to add additional sensors to the on-board battery charger module. However, such additional sensors result in increased cost associated with the battery charger module, with the amount of increased costs depending upon the complexity of the AC voltage sensing circuit (e.g., with or without second zero crossing detection). Additional sensors also require valuable printed circuit board (PCB) space, which is problematic as smaller packages are required for on-board charger modules.
Thus, there exists a need for a battery charger module for an EV or PHEV and an associated method for determining the stability of AC power at the input to the battery charger module. Such a battery charger module and method would determine the stability of AC power at the input to the battery charger module without the need or use of additional AC voltage sensors, thereby avoiding increased costs and packaging space for the battery charger module.